class Node:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

class CircularLinkedList:
    def __init__(self):
        self.head = None

    def is_empty(self):
        return self.head is None

    def delete_head(self):
        """删除循环链表的头节点"""
        if self.is_empty():
            return
        # 只有一个节点的情况
        if self.head.next == self.head:
            self.head = None
            return
        # 找到尾节点
        current = self.head
        while current.next != self.head:
            current = current.next
        # 头节点后移，尾节点指向新头节点
        self.head = self.head.next
        current.next = self.head

    def traverse(self):
        if self.is_empty():
            return []
        result = []
        current = self.head
        while True:
            result.append(current.val)
            current = current.next
            if current == self.head:
                break
        return result

# 测试
if __name__ == "__main__":
    cll = CircularLinkedList()
    cll.insert_at_tail(1)
    cll.insert_at_tail(2)
    cll.insert_at_tail(3)
    cll.delete_head()
    print("删除头节点后遍历:", cll.traverse())  # 输出: [2, 3]